A novel demodulation scheme for fiber Bragg grating sensor system

A novel fiber Bragg grating (FBG) wavelength demodulation scheme based on a compound interference configuration is introduced. This scheme measures the strain-induced wavelength-shift of the FBG in terms of phase-shift signal. The sensing resolution and sensitivity were demonstrated to be 6.2 n/spl epsiv/ and 1.59/spl deg//μ/spl epsiv/, respectively, which match the theoretical value of 1.61/spl deg//μ/spl epsiv/ very well.